python: Use __name__ instead of func_name for Py3 compat

Change-Id: I62a9685b4bce7e9012bc65309fcafe26135fde6d
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15997
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

src/python/m5/SimObject.py

@@ -875,7 +875,7 @@ def cxxMethod(*args, **kwargs):
     """Decorator to export C++ functions to Python"""
 
     def decorate(func):
-        name = func.func_name
+        name = func.__name__
         override = kwargs.get("override", False)
         cxx_name = kwargs.get("cxx_name", name)